Increasing greenhouse gas emissions have resulted in greater motivation to find novel carbon dioxide (CO₂) reduction technologies, where the reduction of CO₂ to valuable chemical commodities is desirable. Molybdenum‐dependent formate dehydrogenase (Mo‐FDH) from Escherichia coli is a metalloenzyme that is able to interconvert formate and CO₂. We describe a low‐potential redox polymer, synthesized by a facile method, that contains cobaltocene (grafted to poly(allylamine), Cc‐PAA) to simultaneously mediate electrons to Mo‐FDH and immobilize Mo‐FDH at the surface of a carbon electrode. The resulting bioelectrode reduces CO₂ to formate with a high Faradaic efficiency of 99±5 % at a mild applied potential of −0.66 V vs. SHE.